Communities throughout the Standing Rock (Sioux) Nation in the northern Great Plains are suffering from diet-related diseases. Community members identify specific traditional foods that they know can treat and prevent these diseases. Traditional foods often rely on plants that are found within the Standing Rock landscape, and many elders know how to gather these plants in accordance with cultural values. Interviews with elders reveal a diversity of knowledge about plants. Elders know about different plants, and also hold different knowledge about the same plants. These differences are explained by variation in use. Elders' knowledge about the seasonal availability of plants varies according to microclimatic variables at specific gathering locations, preferences for plants at different stages of development, and gathering strategies for multiple species. Differences in knowledge within communities can represent an adaptive asset. Interviews confirm that elders have adapted to social and ecological change in the past, and that their knowledge is inherently responsive to highly variable weather patterns in the Great Plains. The diversity of knowledge within communities is a source of adaptive capacity that should be reinforced in the context of global climate change. Many elders and other members of Standing Rock communities share a concern that younger generations are not learning to practice traditional foodways. Tribal agencies and local organizations facilitate gathering trips for youth to gain ecological knowledge from elders. A coalition of these groups also began organizing workshops for elders who wished to share their knowledge about traditional foodways with each other. The potential and probable roles of local organizations are often overlooked in studies of indigenous knowledge transmission. Reflective interviews with elders and organization staff investigated changes in perception, human ecological relations, context specificity, and practical wisdom. This approach identified important dimensions of knowledge transmission that can guide similar collaborations in other indigenous communities. Efforts to increase the availability of local food plants on Standing Rock are an attempt to reclaim food sovereignty. Food sovereignty has been asserted as a right to protect local food systems from global trade agreements, but exercises of this right require renewed capabilities to produce and distribute culturally-significant foods. An innovative food assistance program for elders administered by the Standing Rock tribal government helped revitalize local markets and increase the availability of fresh, local gathered and garden produce within communities. As participation in this voucher program and the local food economy expands, organizers considered the spatial arrangement of new food system components. Spatial analysis of voucher issuance and redemption reveals that minimum cost-distances to market explain 33% of the variance in voucher redemption of Standing Rock districts. Cost-distance analysis was also used to compare the effects of potential new market locations on program equity and efficiency for elders and market vendors. The analytical tools that were developed can help planners evaluate spatial factors as they decide where to locate new markets and enhance food sovereignty. Although analyzed as distinct projects for the sake of clarity, the three components of this research were implemented concurrently and specific outcomes were critical to the success of other components. An integrative model was developed to understand these interactions and demonstrate linkages between diversities of knowledge, local organizations' efforts to facilitate knowledge transmission, and the growth of local food systems.